gforth: gforth/float.fs

Diff for /gforth/float.fs between version 1.18 and 1.53

-version 1.18, Tue Nov  7 18:06:40 1995 UTC
+version 1.53, Mon Dec 31 18:40:24 2007 UTC
  Line 1
  Line 1
  Line 1
  \ High level floating point                            14jan94py
- \ Copyright (C) 1995 Free Software Foundation, Inc.
+ \ Copyright (C) 1995,1997,2003,2004,2005,2006,2007 Free Software Foundation, Inc.
  \ This file is part of Gforth.
  \ Gforth is free software; you can redistribute it and/or
  \ modify it under the terms of the GNU General Public License
- \ as published by the Free Software Foundation; either version 2
+ \ as published by the Free Software Foundation, either version 3
  \ of the License, or (at your option) any later version.
  \ This program is distributed in the hope that it will be useful,
  Line 15
  Line 15
  Line 15
  \ GNU General Public License for more details.
  \ You should have received a copy of the GNU General Public License
- \ along with this program; if not, write to the Free Software
+ \ along with this program. If not, see http://www.gnu.org/licenses/.
- \ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  \ 1 cells 4 = [IF]
  \ ' cells   Alias sfloats
- Line 43
+ Line 42
  Line 43
  Line 42
  \ [THEN]
  : sfalign ( -- ) \ float-ext s-f-align
+     \G If the data-space pointer is not single-float-aligned, reserve
+     \G enough space to align it.
      here dup sfaligned swap ?DO  bl c,  LOOP ;
  : dfalign ( -- ) \ float-ext d-f-align
+     \G If the data-space pointer is not double-float-aligned, reserve
+     \G enough space to align it.
      here dup dfaligned swap ?DO  bl c,  LOOP ;
-sfloats constant sfloat+ ( sf-addr1 -- sf-addr2 ) \ float-ext s-float-plus
+ (Field) sfloat+ ( sf-addr1 -- sf-addr2 ) \ float-ext s-float-plus
- dofield: lastxt code-address! \ change the constant into a field
+ \G @code{1 sfloats +}.
+sfloats ,
+ (Field) dfloat+ ( df-addr1 -- df-addr2 ) \ float-ext d-float-plus
+ \G @code{1 dfloats +}.
+dfloats ,
+ : f, ( f -- ) \ gforth
+     \G Reserve data space for one floating-point number and store
+     \G @i{f} in the space.
+     here 1 floats allot f! ;
-dfloats constant dfloat+ ( df-addr1 -- df-addr2 ) \ float-ext d-float-plus
+ : fconstant  ( r "name" -- ) \ float f-constant
- dofield: lastxt code-address! \ change the constant into a field
- : f, ( f -- )  here 1 floats allot f! ;
- : fconstant  ( r -- ) \ float
      Create f,
  DOES> ( -- r )
      f@ ;
- : fdepth  ( -- n )  f0 @ fp@ - [ 1 floats ] Literal / ;
+ : fdepth ( -- +n ) \ float f-depth
+     \G @i{+n} is the current number of (floating-point) values on the
- : FLit ( -- r )  r> dup f@ float+ >r ;
+     \G floating-point stack.
- : FLiteral ( r -- )
+     fp0 @ fp@ - [ 1 floats ] Literal / ;
-   BEGIN  here cell+ dup faligned <>  WHILE  postpone noop  REPEAT
-   postpone FLit  f, ;  immediate
+ : FLiteral ( compilation r -- ; run-time -- r ) \ float f-literal
+     \G Compile appropriate code such that, at run-time, @i{r} is placed
- &15 Value precision
+     \G on the (floating-point) stack. Interpretation semantics are undefined.
- : set-precision  to precision ;
+     BEGIN  here cell+ cell+ dup faligned <>  WHILE  postpone noop  REPEAT
+     postpone ahead here >r f, postpone then
+     r> postpone literal postpone f@ ;  immediate
+ &15 Value precision ( -- u ) \ float-ext
+ \G @i{u} is the number of significant digits currently used by
+ \G @code{F.} @code{FE.} and @code{FS.}
+ : set-precision ( u -- ) \ float-ext
+     \G Set the number of significant digits currently used by
+     \G @code{F.} @code{FE.} and @code{FS.} to @i{u}.
+     to precision ;
  : scratch ( r -- addr len )
    pad precision - precision ;
- Line 82
+ Line 100
  Line 82
  Line 100
    IF  2drop  scratch 3 min type  rdrop  EXIT  THEN
    IF  '- emit  THEN ;
- : f.  ( r -- )  f$ dup >r 0<
+ : f.  ( r -- ) \ float-ext f-dot
+ \G Display (the floating-point number) @i{r} without exponent,
+ \G followed by a space.
+   f$ dup >r 0<=
    IF    '0 emit
    ELSE  scratch r@ min type  r@ precision - zeros  THEN
    '. emit r@ negate zeros
- Line 90
+ Line 111
  Line 90
  Line 111
  \ I'm afraid this does not really implement ansi semantics wrt precision.
  \ Shouldn't precision indicate the number of places shown after the point?
- : fe. ( r -- )  f$ 1- s>d 3 fm/mod 3 * >r 1+ >r
+ \ Why do you think so? ANS Forth appears ambiguous on this point. -anton.
-   scratch r@ min type '. emit  scratch r> /string type
+ : fe. ( r -- ) \ float-ext f-e-dot
+ \G Display @i{r} using engineering notation (with exponent dividable
+ \G by 3), followed by a space.
+   f$ 1- s>d 3 fm/mod 3 * >r 1+ >r
+   scratch r@ tuck min tuck - >r type r> zeros
+   '. emit scratch r> /string type
    'E emit r> . ;
- : fs. ( r -- )  f$ 1-
+ : fs. ( r -- ) \ float-ext f-s-dot
+ \G Display @i{r} using scientific notation (with exponent), followed
+ \G by a space.
+   f$ 1-
    scratch over c@ emit '. emit 1 /string type
    'E emit . ;
- require debugging.fs
+ : sfnumber ( c-addr u -- r true | false )
+dup [CHAR] e scan ( c-addr u c-addr2 u2 )
- : sfnumber ( c-addr u -- r / )
-dup [CHAR] e scan
      dup 0=
      IF
-drop 2dup [CHAR] E scan
+drop 2dup [CHAR] E scan ( c-addr u c-addr3 u3 )
      THEN
      nip
      IF
-dup >float
+         >float
-         IF
+     ELSE
-drop state @
+drop false
+     THEN ;
+ [ifundef] compiler-notfound1
+ defer compiler-notfound1
+ ' no.extensions IS compiler-notfound1
+ :noname compiler-notfound1 execute ; is compiler-notfound
+ defer interpreter-notfound1
+ ' no.extensions IS interpreter-notfound1
+ :noname interpreter-notfound1 execute ; is interpreter-notfound
+ [then]
+ :noname ( c-addr u -- ... xt )
+dup sfnumber
              IF
-                 POSTPONE FLiteral
+drop [comp'] FLiteral
-             THEN
+     ELSE
-             EXIT
+         defers compiler-notfound1
-         THEN
+     ENDIF ;
-     THEN
+ IS compiler-notfound1
-     defers notfound ;
- ' sfnumber IS notfound
+ :noname ( c-addr u -- ... xt )
+dup sfnumber
+     IF
+drop ['] noop
+     ELSE
+         defers interpreter-notfound1
+     ENDIF ;
+ IS interpreter-notfound1
- : fvariable ( -- )
+ : fvariable ( "name" -- ) \ float f-variable
      Create 0.0E0 f, ;
      \ does> ( -- f-addr )
-.0e0 fasin 2.0e0 f* fconstant pi
+.0e0 fasin 2.0e0 f* fconstant pi ( -- r ) \ gforth
+ \G @code{Fconstant} -- @i{r} is the value pi; the ratio of a circle's area
- : f2*  2.0e0 f* ;
+ \G to its diameter.
- : f2/  0.5e0 f* ;
- : 1/f  1.0e0 fswap f/ ;
+ : f2* ( r1 -- r2 ) \ gforth
+     \G Multiply @i{r1} by 2.0e0
+.0e0 f* ;
+ : f2/ ( r1 -- r2 ) \ gforth
+     \G Multiply @i{r1} by 0.5e0
+.5e0 f* ;
+ : 1/f ( r1 -- r2 ) \ gforth
+     \G Divide 1.0e0 by @i{r1}.
+.0e0 fswap f/ ;
+ get-current environment-wordlist set-current
+.7976931348623157e308 FConstant max-float
+ set-current
  \ We now have primitives for these, so we need not define them
- Line 145
+ Line 208
  Line 145
  Line 208
  \ : facosh   fdup fdup f* 1.0e0 f- fsqrt f+ fln ;
  \ : fasinh   fdup fdup f* 1.0e0 f+ fsqrt f/ fatanh ;
- \ !! factor out parts
+ : f~abs ( r1 r2 r3 -- flag ) \ gforth
- : f~ ( f1 f2 f3 -- flag ) \ float-ext
+     \G Approximate equality with absolute error: |r1-r2|<r3.
+     frot frot f- fabs fswap f< ;
+ : f~rel ( r1 r2 r3 -- flag ) \ gforth
+     \G Approximate equality with relative error: |r1-r2|<r3*|r1+r2|.
+         frot frot fover fabs fover fabs f+ frot frot
+         f- fabs frot frot f* f< ;
+ : f~ ( r1 r2 r3 -- flag ) \ float-ext f-proximate
+     \G ANS Forth medley for comparing r1 and r2 for equality: r3>0:
+     \G @code{f~abs}; r3=0: bitwise comparison; r3<0: @code{fnegate f~rel}.
      fdup f0=
-     IF
+     IF \ bitwise comparison
-         fdrop f= EXIT
+         fp@ float+ 1 floats over float+ over str=
+         fdrop fdrop fdrop
+         EXIT
      THEN
      fdup f0>
      IF
-         frot frot f- fabs fswap
+         f~abs
      ELSE
-         fnegate frot frot fover fabs fover fabs f+ frot frot
+         fnegate f~rel
-         f- fabs frot frot f*
+     THEN ;
-     THEN
-     f< ;
+ \ proposals from Krishna Myeni in <cjsp2d$47l$1@ngspool-d02.news.aol.com>
+ \ not sure if they are a good idea
- : f.s  ." <" fdepth 0 .r ." > " fdepth 0 max maxdepth-.s @ min dup 0
+ : FTRUNC ( r1 -- r2 )
-   ?DO  dup i - 1- floats fp@ + f@ f.  LOOP  drop ;
+     \ round towards 0
+     \ !! should be implemented properly
+     F>D D>F ;
+ : FMOD ( r1 r2 -- r )
+     \ remainder of r1/r2
+     FOVER FOVER F/ ftrunc F* F- ;

-Generate output suitable for use with a patch program
+Legend:



Removed from v.1.18
 


changed lines


 
Added in v.1.53
 Legend:



Removed from v.1.18
 


changed lines


 
Added in v.1.53
-Removed from v.1.18
+Added in v.1.53

CVS Admin

gforth: gforth/float.fs

Diff for /gforth/float.fs between version 1.18 and 1.53

ViewCVS and CVS Help